Kommentar zu Bereschit 37:21

לא נכנו נפש — supply the word מכת so that the meaning will be “Let us not smite him with a smiting of his life” — it means killing.

ויצילהו מידם, he saved his life, no more.

ויצילהו מידם, by first of all preventing immediate action by the brothers, committing an act which would prove to be irrevocable. This would have been the kind of thing Solomon had in mind when he said in Kohelet 1,15 that מעוות לא יוכל לתקן, “there are things so twisted that they are beyond repair.” He referred to matters from which sometimes the righteous person can also not be saved. One such example was the irreversible act of Reuven of having slept with Bilhah. Yaakov himself characterized it as פחז כמים, “hasty like water” (flowing downstream, something beyond recall).

ויצילהו מידם. "He saved him from harm at their hands. This action was applauded by the Torah as man is a free creature possessing freedom of choice and able to kill people who are not guilty or have not been convicted, as distinct from wild beasts which do not kill humans unless the latter are guilty of death in the eyes of G'd. The words ויצילהו מידם mean that he saved them from the evil consequences of carrying out their freedom of choice to kill. By doing what he did Reuben nullified the brothers' statement: "we shall see what happens to his dreams."

וישמע...לא נכנו נפש, killing.

לא נכנו נפש, “let us not commit murder. Reuven found it impossible to agree with the advice, i.e. the solution proposed by his brothers. He intended to save Joseph. Had he said immediately: “we will not kill him,” he would have given away his intention to save Joseph and the fact that he had pity on him. He therefore added the word נפש to convince his brothers that his strategy was not aimed at saving Joseph’s fate but at saving his brothers from committing an unpardonable sin The prohibition of murdering someone in cold blood is absolute and knows of no exceptions. This is why he added אל תשפכו דם, “do not spill blood.” Had he been concerned only with Joseph’s blood not being spilled he would have said אל תשפכו דמו, “do not spill his blood.” He implied that he shared the brothers’ evaluation of Joseph’s guilt and hated him just as they hated him, but that he was concerned with the basic prohibition of shedding the blood of a human being, נפש.

A blow to the soul, which refers to killing. Otherwise, how does נכנו — the object of which is Yoseif — connect to the following word נפש? Thus Rashi explains that the verse is as if it said מכת נפש, [which is an adverbial phrase modifying נכנו]. (R. Meir Stern)

Reubens Verhältnis zu den Brüdern, wie er in dieser Begebenheit auftritt, dürfte rätselhaft erscheinen. Er scheint nur zufällig bei ihnen zu sein, da er ja sich sehr bald wieder von ihnen entfernt haben muss, und bei der eigentlichen Entwicklung gar nicht gegenwärtig war. Ob er überhaupt als בכור an den gewöhnlichen Tagesbeschäftigungen nicht Teil zu nehmen hatte, ob er schon im allgemeinen von ihren Ansichten über Josef differierte und daher an den Absichten und Beratungen, die sie nach Sichem geführt, nicht teilnehmen wollte, dürfte zweifelhaft sein. Wir werden noch Raw Hirsch on Genesis 37: 30. wieder darauf zurückkommen. — לא נכנו נפש ist ganz positiRaw Hirsch on Genesis 37: Einen solchen Gedanken, wie ihr eben angeregt, werden wir nicht ausführen. Ich, als der ältere Bruder, leide das nicht. Indem Raw Hirsch on Genesis 37: 22 nochmals seine Rede eingeleitet wird, scheint es erst Diskussion gegeben zu haben, worauf er dann, um sie zu beschwichtigen, mit dem andern Vorschlag hervortrat.

וישמע ראובן ויצילהו מידם, “when Reuven heard this he saved him from them. G-d decided at that moment that because it was Reuven who had made the first move to save Joseph, the cities of refuge in Israel later on would begin with those in the territory allocated to the tribe of Reuven. (B’reshit Rabbah 84,15) This is also hinted at in Deuteronomy 4,43: את בצר במישור לראובני, “Bezer in the tableland to the members of the tribe of Reuven.”

לא נכנו נפש. "Let us not kill him." What Reuben meant was "let us not kill him outright ourselves but only cause his death indirectly." When he said later: "do not shed blood, throw him into the pit," this was his argument to his brothers. He only pretended to agree that Joseph's death should be caused because he could think of no other way of saving Joseph's life and restoring him to his father. He was quite certain in his own mind that no wild beast would harm Joseph, or any other of Jacob's sons for that matter. He himself would also not allow Joseph to remain in the pit long enough to die of hunger. Proof of Reubens' intention is that the Torah reports that he returned to the pit shortly after the brothers had sold Joseph in his absence. He had planned to take Joseph out of the pit.